1. Field of the Invention
The present invention relates to a vacuum cleaner, and particularly to a vacuum cleaner with an improved dust collecting capability.
2. Description of the Background Art
Vacuum cleaners are generally classified into those of a canister type and of an upright type. When cleaning with the canister type vacuum cleaner, one must drag through a long hose the body of the cleaner, in which an electric motor is stored, to move its suction opening to a place to be cleaned. The upright type cleaner, however, has a body with such a suction opening and an electric motor integrated therein, which allows easy operation.
Referring to FIGS. 1 and 2, a conventional upright type vacuum cleaner includes a main body 1; a handle 1-1 attached to an upper portion of the body 1 for operating the cleaner; wheels 2 attached to a lower portion of body 1 and rotating corresponding to the operation of handle 1-1; a fan motor 3 for exhaust contained in a lower portion of body 1; a dust-collecting bag 1-2 contained within body 1 above fan motor 3; a hose 11; a floor nozzle 5, pivotally attached to body 1 with an angle in a certain range by attaching means with a coaxial shaft 4 of fan motor 3 as its pivot, and in communication with dust-collecting bag 1-2 via hose 11; a rotary brush member 7 provided within floor nozzle 5; a pulley (not shown) attached to an end of rotary brush member 7; a belt 6 suspended between coaxial shaft 4 of fan motor 3 and the pulley for transmitting the power of fan motor 3 to rotary brush member 7; an extension pipe 11-1 and a narrow space nozzle 11-2 both connected to a tip end of hose 11 when cleaning a corner of a room, a space between pieces of furniture, etc., for cleaning such narrow spaces difficult to insert floor nozzle 5 therein; and a power supply cord (not shown). An exhaust outlet 12 for fan motor 3 is formed at a lower portion of main body 1.
Rotary brush member 7 has a surface with bristles spirally planted thereon. When cleaning a carpet, dust is raked by these bristles, and is sucked and sent into dust-collecting bag 1-2. When cleaning a floor or the like, rotation of rotary brush member 7 can be stopped.
A wall is provided around rotary brush member 7 to form a suction opening. Of the suction opening, a side in contact with a floor surface is open, whereas the other side not in contact with the floor is separated from outside-air, and the dust sucked from a suction member connected to hose 11 is sent into the dust-collecting bag. The suction member is provided in the vicinity of the center portion of rotary brush member 7, or in a structure as shown in FIG. 1, at a portion opposite to an end of rotary brush member 7.
Negative pressure around the rotary brush member decreases in proportion to the volume of the dust sucked during cleaning; sucking force decreases at a farther distance from the suction member. With a conventional vacuum cleaner, dust raked by the rotary brush member has been sucked only with sucking force provided to the suction member by fan motor 3. This has resulted in poor efficiency in sucking dust.